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<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <script>
        //报错1
        // export 1;

        //报错2
        // export m;
        // vara m =1;


        //正确写法一
        export var m = 1;

        //正确写法二
        var m = 1;
        export{m};

        //正确写法三
        var n = 1;
        export{n as m};
    </script>
</body>
</html>